<?php

class Inflector {

    public static $regexUninflectedPlural;
    public static $regexIrregularPlural;
    public static $regexUninflectedSingular;
    public static $regexIrregularSingular;

    public static function camelize($lowerCaseAndUnderscoredWord) {
        return str_replace(" ", "", ucwords(str_replace("_", " ", $lowerCaseAndUnderscoredWord)));
    }

    public static function underscore($camelCasedWord) {
        return strtolower(preg_replace('/(?<=\\w)([A-Z])/', '_\\1', $camelCasedWord));
    }

    public static function enclose($string) {
        return '(?:' . $string . ')';
    }

    public static function pluralize($word) {

        if (isset(self::$pluralized[$word])) {
            return self::$pluralized[$word];
        }

        if (!isset(self::$regexUninflectedPlural) || !isset(self::$regexIrregularPlural)) {
            self::$regexUninflectedPlural = self::enclose(join( '|', self::$irregularPlural));
            self::$regexIrregularPlural = self::enclose(join( '|', array_keys(self::$irregularPlural)));
        }

        if (preg_match('/(.*)\\b(' . self::$regexIrregularPlural . ')$/i', $word, $regs)) {
            self::$pluralized[$word] = $regs[1] . substr($word, 0, 1) . substr(self::$irregularPlural[strtolower($regs[2])], 1);
            return self::$pluralized[$word];
        }

        if (preg_match('/^(' . self::$regexUninflectedPlural . ')$/i', $word, $regs)) {
            self::$pluralized[$word] = $word;
            return $word;
        }

        foreach (self::$pluralRules as $rule => $replacement) {
            if (preg_match($rule, $word)) {
                self::$pluralized[$word] = preg_replace($rule, $replacement, $word);
                return self::$pluralized[$word];
            }
        }
    }

    public static function singularize($word) {
        if (isset(self::$singularized[$word])) {
            return self::$singularized[$word];
        }

        if (!isset(self::$regexUninflectedSingular) || !isset(self::$regexIrregularSingular)) {
            self::$regexUninflectedSingular = self::enclose(join( '|', self::$uninflectedSingular));
            self::$regexIrregularSingular = self::enclose(join( '|', array_keys($irregularSingular)));
        }

        if (preg_match('/(.*)\\b(' . self::$regexIrregularSingular . ')$/i', $word, $regs)) {
            self::$singularized[$word] = $regs[1] . substr($word, 0, 1) . substr(self::$irregularSingular[strtolower($regs[2])], 1);
            return self::$singularized[$word];
        }

        if (preg_match('/^(' . $regexUninflectedSingular . ')$/i', $word, $regs)) {
            self::$singularized[$word] = $word;
            return $word;
        }

        foreach (self::$singularRules as $rule => $replacement) {
            if (preg_match($rule, $word)) {
                self::$singularized[$word] = preg_replace($rule, $replacement, $word);
                return self::$singularized[$word];
            }
        }
        self::$singularized[$word] = $word;
        return $word;
    }

    public static $pluralized = array();

    public static $singularized = array();

    public static $pluralRules = array(
        '/(s)tatus$/i' => '\1\2tatuses',
        '/(quiz)$/i' => '\1zes',
        '/^(ox)$/i' => '\1\2en',
        '/([m|l])ouse$/i' => '\1ice',
        '/(matr|vert|ind)(ix|ex)$/i'  => '\1ices',
        '/(x|ch|ss|sh)$/i' => '\1es',
        '/([^aeiouy]|qu)y$/i' => '\1ies',
        '/(hive)$/i' => '\1s',
        '/(?:([^f])fe|([lr])f)$/i' => '\1\2ves',
        '/sis$/i' => 'ses',
        '/([ti])um$/i' => '\1a',
        '/(p)erson$/i' => '\1eople',
        '/(m)an$/i' => '\1en',
        '/(c)hild$/i' => '\1hildren',
        '/(buffal|tomat)o$/i' => '\1\2oes',
        '/(alumn|bacill|cact|foc|fung|nucle|radi|stimul|syllab|termin|vir)us$/i' => '\1i',
        '/us$/' => 'uses',
        '/(alias)$/i' => '\1es',
        '/(ax|cri|test)is$/i' => '\1es',
        '/s$/' => 's',
        '/^$/' => '',
        '/$/' => 's');

    public static $uninflectedPlural = array(
        '.*[nrlm]ese', '.*deer', '.*fish', '.*measles', '.*ois', '.*pox', '.*sheep', 'Amoyese',
        'bison', 'Borghese', 'bream', 'breeches', 'britches', 'buffalo', 'cantus', 'carp', 'chassis', 'clippers',
        'cod', 'coitus', 'Congoese', 'contretemps', 'corps', 'debris', 'diabetes', 'djinn', 'eland', 'elk',
        'equipment', 'Faroese', 'flounder', 'Foochowese', 'gallows', 'Genevese', 'Genoese', 'Gilbertese', 'graffiti',
        'headquarters', 'herpes', 'hijinks', 'Hottentotese', 'information', 'innings', 'jackanapes', 'Kiplingese',
        'Kongoese', 'Lucchese', 'mackerel', 'Maltese', 'media', 'mews', 'moose', 'mumps', 'Nankingese', 'news',
        'nexus', 'Niasese', 'Pekingese', 'People', 'Piedmontese', 'pincers', 'Pistoiese', 'pliers', 'Portuguese', 'proceedings',
        'rabies', 'rice', 'rhinoceros', 'salmon', 'Sarawakese', 'scissors', 'sea[- ]bass', 'series', 'Shavese', 'shears',
        'siemens', 'species', 'swine', 'testes', 'trousers', 'trout', 'tuna', 'Vermontese', 'Wenchowese',
        'whiting', 'wildebeest', 'Yengeese');

    public static $irregularPlural = array(
        'atlas' => 'atlases',
        'beef' => 'beefs',
        'brother' => 'brothers',
        'child' => 'children',
        'corpus' => 'corpuses',
        'cow' => 'cows',
        'ganglion' => 'ganglions',
        'genie' => 'genies',
        'genus' => 'genera',
        'graffito' => 'graffiti',
        'hoof' => 'hoofs',
        'loaf' => 'loaves',
        'man' => 'men',
        'money' => 'monies',
        'mongoose' => 'mongooses',
        'move' => 'moves',
        'mythos' => 'mythoi',
        'numen' => 'numina',
        'occiput' => 'occiputs',
        'octopus' => 'octopuses',
        'opus' => 'opuses',
        'ox' => 'oxen',
        'penis' => 'penises',
        'person' => 'people',
        'sex' => 'sexes',
        'soliloquy' => 'soliloquies',
        'testis' => 'testes',
        'trilby' => 'trilbys',
        'turf' => 'turfs');

    public static $singularRules = array(
        '/(s)tatuses$/i' => '\1\2tatus',
        '/^(.*)(menu)s$/i' => '\1\2',
        '/(quiz)zes$/i' => '\\1',
        '/(matr)ices$/i' => '\1ix',
        '/(vert|ind)ices$/i' => '\1ex',
        '/^(ox)en/i' => '\1',
        '/(alias)(es)*$/i' => '\1',
        '/(alumn|bacill|cact|foc|fung|nucle|radi|stimul|syllab|termin|viri?)i$/i' => '\1us',
        '/(cris|ax|test)es$/i' => '\1is',
        '/(shoe)s$/i' => '\1',
        '/(o)es$/i' => '\1',
        '/ouses$/' => 'ouse',
        '/uses$/' => 'us',
        '/([m|l])ice$/i' => '\1ouse',
        '/(x|ch|ss|sh)es$/i' => '\1',
        '/(m)ovies$/i' => '\1\2ovie',
        '/(s)eries$/i' => '\1\2eries',
        '/([^aeiouy]|qu)ies$/i' => '\1y',
        '/([lr])ves$/i' => '\1f',
        '/(tive)s$/i' => '\1',
        '/(hive)s$/i' => '\1',
        '/(drive)s$/i' => '\1',
        '/([^fo])ves$/i' => '\1fe',
        '/(^analy)ses$/i' => '\1sis',
        '/((a)naly|(b)a|(d)iagno|(p)arenthe|(p)rogno|(s)ynop|(t)he)ses$/i' => '\1\2sis',
        '/([ti])a$/i' => '\1um',
        '/(p)eople$/i' => '\1\2erson',
        '/(m)en$/i' => '\1an',
        '/(c)hildren$/i' => '\1\2hild',
        '/(n)ews$/i' => '\1\2ews',
        '/^(.*us)$/' => '\\1',
        '/s$/i' => '');

    public static $uninflectedSingular = array(
        '.*[nrlm]ese', '.*deer', '.*fish', '.*measles', '.*ois', '.*pox', '.*sheep', '.*ss', 'Amoyese',
        'bison', 'Borghese', 'bream', 'breeches', 'britches', 'buffalo', 'cantus', 'carp', 'chassis', 'clippers',
        'cod', 'coitus', 'Congoese', 'contretemps', 'corps', 'debris', 'diabetes', 'djinn', 'eland', 'elk',
        'equipment', 'Faroese', 'flounder', 'Foochowese', 'gallows', 'Genevese', 'Genoese', 'Gilbertese', 'graffiti',
        'headquarters', 'herpes', 'hijinks', 'Hottentotese', 'information', 'innings', 'jackanapes', 'Kiplingese',
        'Kongoese', 'Lucchese', 'mackerel', 'Maltese', 'media', 'mews', 'moose', 'mumps', 'Nankingese', 'news',
        'nexus', 'Niasese', 'Pekingese', 'Piedmontese', 'pincers', 'Pistoiese', 'pliers', 'Portuguese', 'proceedings',
        'rabies', 'rice', 'rhinoceros', 'salmon', 'Sarawakese', 'scissors', 'sea[- ]bass', 'series', 'Shavese', 'shears',
        'siemens', 'species', 'swine', 'testes', 'trousers', 'trout', 'tuna', 'Vermontese', 'Wenchowese',
        'whiting', 'wildebeest', 'Yengeese');

    public static $irregularSingular = array(
        'atlases' => 'atlas',
        'beefs' => 'beef',
        'brothers' => 'brother',
        'children' => 'child',
        'corpuses' => 'corpus',
        'cows' => 'cow',
        'ganglions' => 'ganglion',
        'genies' => 'genie',
        'genera' => 'genus',
        'graffiti' => 'graffito',
        'hoofs' => 'hoof',
        'loaves' => 'loaf',
        'men' => 'man',
        'monies' => 'money',
        'mongooses' => 'mongoose',
        'moves' => 'move',
        'mythoi' => 'mythos',
        'numina' => 'numen',
        'occiputs' => 'occiput',
        'octopuses' => 'octopus',
        'opuses' => 'opus',
        'oxen' => 'ox',
        'penises' => 'penis',
        'people' => 'person',
        'sexes' => 'sex',
        'soliloquies' => 'soliloquy',
        'testes' => 'testis',
        'trilbys' => 'trilby',
        'turfs' => 'turf');
}